How to make a stackup instruction for multilayer PCB to PCB factory?

1. by *.TXT file

————————————–  Layer 1 ( Final Copper  1 OZ )
Prepreg  0.1mm
————————————–  Layer 2 (  Start Copper  1 OZ, Control  Impedance single end: 5mil, 50 +/-5 Ohm,REF. L1,L3 )
FR4 Core 0.3mm
————————————–  Layer 3 (  Start Copper  1 OZ )
Prepreg  0.1mm
————————————–  Layer 4 (  Start Copper  1 OZ )
Fr4 Core 0.3mm
—————————————Layer 5 (  Start Copper  1 OZ, Control Impedance Differential:  5mil/5mil,  100+/10Ohm,Ref.L4,L6  )
Prepreg  0.1mm
————————————–  Layer 6 ( Final Copper   1 OZ )

Finished PCB thickness 1.2mm +/-0.12mm (Include solder mask)
Download TXT file  readme